1945 US could've conquered the world (it couldn't)

I would say the US in the 90s was considerably relatively weaker than 1945 US. Considerably. 1945 US could have conquered the world, if it had set its mind to doing so. 1990s US? Not a chance. Once the USSR had nukes, the playing field permanently became far, far more level/equal. Again, the US was the only country with nukes, had the majority of the world's ships/carriers, had the biggest air force in the world by a factor of 2x or more, and controlled 80% of the world's oil supply. Its hard to overstate how big of a deal that is.